I understand that weather on TV can’t be hyperlocally accurate. But a weather app on my phone has my exact GPS coordinates. Why can’t it tell me exactly when a rain cloud will be passing over my location?
It’s gotten to the point where I just use precipitation maps to figure out my rain chances for the day.
The hourly forecast is mostly useless because it’s not a chance % but a % of the area that will be raining.
I am a pilot and flight instructor. I took a full year of meteorology at ERAU. Most weather forecast products presented to the general public are completely worthless, and we really should run “AccuWeather” out of business.
The temperature number they show you for what it is “now” was probably taken by the AWOS at the closest municipal airport to your location. If you’ve ever noticed like a car GPS reporting weather from three towns over and not the one you’re in right now, it’s because the town you’re in right now doesn’t have a nearby airport or it doesn’t have an AWOS.
10-day forecasts are generated by tarot cards and have no basis in reality. Actual aviation weather forecasts seldom reach out beyond 24 hours.
Your best bet for getting a complete understanding of the weather is to start by looking at the GOES satellite imagery, ie actually look at the Earth from geosynchronous orbit and look at the clouds. You know those maps with the blue lines with triangles on them and red lines with half circles and big blue Hs and big red Ls? Those are called Prognostic charts, those map where high and low pressure systems and fronts are. Look at one of those and compare them to the satellite images. Then look at Doppler radar imagery, which shows where precipitation is. Look at what it’s been doing for the last few hours, and then you can get a good sense of generally what the weather is going to do in the next few hours. Beyond that, not even God knows because the prick hasn’t decided yet.
It amazes me how some people seem to go through life not realizing weather is fundamentally chaotic.
Like, even if all you do is look out a window from time to time…
Weather prediction at point locations is extremely challenging to get right because we simply can’t observe and make predictions for every single square inch of the earth. Many weather models are run on grids with boxes about the size of a few kilometers at the smallest scale, which means that any physical process in the atmosphere that is the size of that box or smaller won’t be represented well by the model.
Specifically on your point about clouds passing over your location, cloud and precipitation formation is even more challenging. Clouds and precipitation form due to atmospheric processes ranging from hundreds of kilometers all the way down to micrometers, which practically means the weather models are making an educated guess (albeit a very good one that is informed by scientific research) about when and where clouds will form. And when a model does predict a cloud, it will cover an entire grid box.
Finally, I saw you made a comment about how machine learning should improve forecasts, and in fact it does! But the weather community is still working on data driven models (as opposed to models that solve physical atmospheric equations), and most of them are run by private companies so their output is not free. As these data driven models get better, it may be possible that they will be able to make predictions at scales less than a kilometer.
Since people are sharing their weather apps, I use Breezy Weather! Multiple sources, lots of info, FOSS, what’s not to like. I tried multiple sources untill I found one that was the most accurate for me.
Weather apps don’t do real time analytics, but show you the forecast some nearby weather station has calculated. Whether that’s based on current data or a couple hours ago depends on the exact provider they use. And hardly anyone of those are done by actual humans, it’s aggregated statistics.
If you look at precipitation maps, you are doing that forecast by yourself based on cloud movements and local knowledge, something no machine-generated forecast can do as good.
Plus, there’s usually one weather station covering a large area, so hyperaccurate predictions would have to be made just for you - which simply costs to much.
Darksky could do it back in the day more or less. you’d get messages that it would rain in about 15 minutes and stop in the next 30.
Thing is, precep maps don’t work everywhere. You’re probably in a location like me where a thick front rolling through will almost always bring rain. If you get into warmer tropical climates, rainclouds will just poof out of nowhere and drop rain on your ass while other crazy fronts will pass over with nothing but some dark clouds.
But a weather app on my phone has my exact GPS coordinates. Why can’t it tell me exactly when a rain cloud will be passing over my location?
Because they’ve never been able to do that…
When they say “50% chance of rain”, it doesn’t meant there’s a 50/50 chance it rains where you’re located
It’s that for the broadcast area, about half is gonna get rain.
Unless I misunderstood what you said, that’s not it either. 50% chance of rain means exactly that: according to their forecast models, there is a 50% change it will rain. Snopes did a writeup of this.
Can’t trust snopes any more
Says who? And what evidence?
Reading Snopes will give you plenty. Read the articles - and a lot of them use weasel-wording to push the result they want.
I don’t have the exact article on hand at the moment, but an example would be someone claiming that clear-cutting 1000 acres of trees would destroy [X]^3 of CO2 reduction; and then Snopes will “fact check” it by saying they aren’t cutting down 1000 acres of trees this year. Often times they’ll ‘debunk’ something that sounds like the claim, but isn’t the actual claim.
That’s not a correct understanding of how Snopes works. They debunked this.
We’ve investigated ourselves, and have found nothing wrong!
For one thing, there’s two competing weather services providing the data to countless apps in the US and one of them has more money to throw around than the other.
The weather channel has better weather predictions overall than Apple’s own weather app, as rated by Forecastadvisor.com, but is not as accurate as Accuweather is although it’s used in more apps.
Weather is about tracking and predictions. It’s never going to be completely 100% correct. But taking a hodgepodge of information from several prediction services means you’re more likely to be less accurate overall despite what people may think.
All of those weather services just pull data from NOAA. There’s no competition, besides making up stuff beyond what NOAA predicts.
If all the private company weather services were only getting their info from the NOAA we wouldn’t have such varying results most of the time. Which is basically my point. The results vary because they don’t just use the NOAA’s data and predictions. The second one is actually the US Armed Forces.
Their results vary because, like I said, they just make shit up. They have their own formulas using NOAA and other government data, but they’re still just making it up to look like they provide value so you’ll pay for their services. There’s other global weather models, like ECMWF, but they’re all government orgs. Windy has a great article on it. https://windy.app/blog/ecmwf-vs-gfs-differences-accuracy.html
If your app doesn’t tell you where it’s getting its data from then it’s using GFS from NOAA and it’s charging you for the free data it gets from there.
MinuteCast from AccuWeather does exactly this. It looks at your location, looks at radar data for storm systems approaching your location, and estimates when precipitation will start at your location and how intense it will be. It’s generally pretty accurate, with some limitations. It seems to be pretty good for consistent rainstorms but it can get tripped up by pop-up thunderstorms, where the radar track can go suddenly from no rain to downpour. It doesn’t make predictions more then 2-3 hours out because past that timeframe it’s not easy to predict if weather will continue on its current track or change direction. Even with the limitations, I use it all the time. Mostly to tell if I should take the dogs out right away, or if I should wait an hour or two.
This is exactly what I’m looking for! I also often check the weather to get a gauge on whether it’s clear to walk my dogs. 2-3 hours ahead is perfect.
